You can configure the DNS servers manually in your macOS settings. These are the steps to follow:
1. Go to System Preferences, then Network.
2. Choose the network interface you are using, and click on Advanced...
3. Open the DNS tab, and click on the + button at the bottom to add the DNS addresses of CyberGhost servers :
4. Click on OK and that's it!
For any additional information or concerns - it is best to approach the Support Department:
via e-mail: firstname.lastname@example.org
via on-line request: https://support.cyberghostvpn.com/hc/en-us/requests/new
via 24/7 Live! Chat Sessions on our website